Various types of mechanical depilatory devices have been proposed and are known in the marketplace.
In applicants' U.S. Pat. No. 4,524,772 there is described an electrically powered depilatory device including a hand held portable housing, motor apparatus disposed in the housing, and a helical spring comprising a plurality of adjacent windings arranged to be driven by the motor apparatus in rotational sliding motion relative to the skin bearing hair to be removed, the helical spring including an arcuate hair engaging portion arranged to define a convex side whereat the windings are spread apart and a concave side corresponding thereto whereat the windings are pressed together, the rotational motion of the helical spring producing continuous motion of the windings from a spread apart orientation at the convex side to a pressed together orientation at the concave side for engagement and plucking of hair from the skin, whereby the surface velocities of the windings relative to the hair greatly exceeds the surface velocity of the housing relative thereto.
The above-described device has met with very considerable commercial success throughout the world. The Background of the Invention section of U.S. Pat. No. 4,524,772 describes the most relevant prior art relative thereto including, inter alia, Swiss Patent 268,696.
Following the publication and public introduction of the above-described device of applicants, additional versions of mechanical depilatory devices have also been proposed, for example in various patents which are exemplary of the art: U.S. Pat. No. 4,079,741; U.S. Pat. No. 4,726,375; U.S. Pat. No. 2,492,484; French Patent 79 10572; French Patent 2,307,491; French Patent 2,454,283; German Offenlegungsschrift 2650969; Swiss Patent 179,261 and U.K. Patent 203,970.